British Transport Police said the girl, from Ellesmere, moved away but he tailed her through several carriages before she left the train. He then pursued the girl along a platform until she got into her father’s car outside the station.

British Transport Police has issued a CCTV image of a man they want to talk to in connection with the incident. Police have only just released details of the alleged crime.

“While clearly it would have been better had this offence not happened, it is reassuring to see our text number being used for exactly what it was set up to do: reporting unwanted sexual behaviour, and that it gave the teen the confidence to contact us.

“We’ve carried out a number of CCTV inquiries on the train and at the station, which have revealed a man on the platform who we’d like to talk to about this assault and I’d urge anyone who knows his identity to call us.”

Anyone with information is asked to contact British Transport Police on 0800 40 50 40, or text 61016, quoting reference B4/WSUB of 1/9/2015.

Information can also be passed anonymously to independent charity Crimestoppers on 0800 555 111.